1. Field of the Invention
This invention is concerned with staging of the type comprising a plurality of decking members arranged in a stepped configuration for supporting a group of people such as in group photography or a standing or seated audience.
2. Description of the Prior Art
Existing staging structures are heavy and bulky to transport and are slow and difficult to erect, particularly on uneven or sloping ground. For example, in one such structure each decking member is supported by two or more timber trestles which must each be individually erected and levelled. In other existing staging the decking members are supported by a scaffolding arrangement comprising numerous bars, clamps and other components which must all be connected together. That structure also has many individually adjustable feet which must all be correctly adjusted to avoid potentially dangerous stresses being produced in the structure. There is also a large wooden structure in commercial use which requires a team of erectors and a fleet of about seven lorries to transport it.
U.S. Pat. No. 4,747,238 discloses portable audience seating in which the decking members are supported by spaced rearwardly inclined truss members. Each truss member is in turn supported by spaced pairs of props or legs arranged in an inverted-V configuration, and the lower ends of each pair of legs are joined by a bracing bar. However, since the legs are not positively connected to the truss members such an arrangement would not be feasible for supporting trusses with a steep inclination of around 45 degrees such as is required for group photography. Moreover, each pair of legs must be individually and accurately levelled to prevent undesirable stresses from being produced in the truss members.
U.S. Pat. No. 1,839,679 discloses a similar form of staging, but here each pair of legs is positively connected to the respective truss member at their upper ends, and a single tie bar connects the centre of each bracing bar to the bottom of the respective truss. Whilst the structural strength and stability of such an arrangement may be better than that of U.S. Pat. No. 4,747,238, it is still considered that such an arrangement would not be acceptable for tall structures with steeply inclined truss members. Similar considerations apply to the structures disclosed in U.S. Pat. No. 2,651,081 and British Patent No. 695,774.